Method and apparatus for manufacture of decorative sheets

ABSTRACT

A method and apparatus for fabricating a decorative sheet or panel by bonding a plurality of veneer sheets to one face of a rigid backing sheet over an intervening layer of an adhesive coating the latter. Stacks of veneers to be adhered to successive backing sheets are held in side-by-side relationship on the movable bottoms of their respective repositories defined by parallel partitions within a rectangular frame. This frame as well as the movable bottoms of the repositories are mounted on a platform which also is moved up and down by first lift means provided therebelow. In operation, the frame is elevated by the first lift means into contact with each backing sheet supported horizontally by an overhead conveyor. Second lift means mounted on the platform is then set in motion to move the stacks of veneers upwardly relative to the frame until the uppermost veneers of the respective stacks are stuck to the lower face of the backing sheet over the layer of adhesive previously coated thereon. Thereafter the remaining stacks of veneers and the frame are successively lowered by the second and the first lift means, respectively. This cycle of operation can be repeated continuously.

United States Patent Umazume 1 1 METHOD AND APPARATUS FOR MANUFACTURE OF DECORATIVE SHEETS 3.830.489 8/1974 Adams 214/115 D X Primary Exuminen-Charles E. Van Horn [76] Inventor: Kousuke Umazume. 13-5, Z-chome, y

shimorenjaku Miwka shi Assistant [swimmer-Thomas 1:, Bokan Tokyo-to, Japan [22] Filed: Jan. 10, 1974 1 1 ABSTRACT [21] Appl NO; 432,332 A method and apparatus for fabricating a decorative sheet or panel by bonding a plurality of veneer sheets n to one face of a rigid backing sheet over an interven- 1 1 Foreign pp D313 ing layer of an adhesive coating the latter. Stacks of July 14, 1973 Ja an 48-82696 veneers to be adhered to successive backing sheets are held in side-by-side relationship on the movable bot- [521 US. Cl. 156/299; 144/245 F; 144/309 R; toms of their respective repositories defined by paral- 144/313; 156/562; 156/565; 214/8.5 A; lel partitions within a rectangular frame. This frame as 214/85 R; 221/209; 271/9; 271/159 well as the movable bottoms of the repositories are [51} Int. Cl..... B32b 31/04; 865g 59/02; B65h 7/00 mounted on a platform which also is moved up and [58] Field of Search 156/562, 565. 299; down by first lift means provided therebelowi In oper- 144/309 R, 313, 315 R, 245 F; 214/85 A, ation, the frame is elevated by the first lift means into 214/85 R 5 ;221/Z09, contact with each backing sheet supported horizori- 221/210,211;271/9,157,158,159 tally by an overhead conveyor Second lift means mounted on the platform is then set in motion to move [56] References Cited the stacks of veneers upwardly relative to the frame UNITED STATES P TE TS until the uppermost veneers of the respective stacks 3 224 919 12]965 Elmcndorf I56/562 X are stuck to the lower face of the backing sheet over 3334'89l 8/1967 Clause c 27; X the layer of adhesive previously coated thereon. 3 5 10/1970 Kener H 214/35 D Thereafter the remaining stacks of veneers and the 3,580,778 5/1971 Lars n 156/562 X frame are successively lowered by the second and the 3,599,968 8/1971 Billett 1 214/85 D X first lift means, respectively. This cycle of operation 3,730,816 5/1973 Crawford 156/299 X can be repeated gontinugusly, 3,765,993 10/1973 Raffensparger et a1 214/85 A X 3,785,508 1/1974 Hayden 271/9 X 5 Claims, 2 Drawing Figures l 22 l 2a 2s 2g 28 1 I 1 l l 1 I a i l l l l 1 -1 l 1 2o 25* F13 war ".tw rti r1 7*: 1-: r: 1 1 A A V l l j PATENTEDJUN 1 7 I975 SHEET FIG.I

METHOD AND APPARATUS FOR MANUFACTURE OF DECORATIVE SHEETS BACKGROUND OF THE INVENTION This invention relates to a method and apparatus for the manufacture of decorative sheets or panels. and more specifically to a fully automated method and apparatus for temporarily adhering a plurality of veneers to one face of each of successively supplied backing sheets of relatively rigid material for the provision of decorative sheets.

Decorative sheets have heretofore been manufactured by temporarily adhering thin strips of veneer sheet to one face of each of relatively rigid backing sheets and then by permanently bonding the veneers to the respective backing sheets under application of heat and pressure. The veneers are ordinarily produced by slicing the logs of zelkova, teak, red sandalwood and like trees to a thickness of from about I). l 5 to LOO millimeter, and the backing sheets may be either in the form of plywood, fiberboard, sheet metal or the like.

The temporary adhesion of the veneers to the backing sheets has been mostly carried out manually. However, since the veneers in use are extremely thin and rather narrow in width, it is highly difficult to manually adhere the veneers to each backing sheet exactly in a specified one of various known patterns. The productivity of the conventional manual operation has thus been very low, and it has required highly skilled labor to produce decorative sheets of unfluctuating quality.

SUMMARY OF THE INVENTION In view of the noted difficulties of the prior art, it is an object of this invention to provide a fully automated method and apparatus for adhering a plurality of thin veneers to one face of each of successively supplied backing sheets in a prescribed pattern for the provision of decorative sheets.

Another object of the invention is to provide a method and apparatus for the automatic manufacture of decorative sheets whereby the veneers can be uniformly and efficiently adhered to each backing sheet, in such a manner that no fissures, undulations, discoloration or other surface irregularities or defects are produced in the veneers adhered to the backing sheet.

A further object of the invention is to provide an apparatus for the automatic manufacture of decorative sheets wherein stacks of veneers to be adhered to the successive backing sheets are always neatly accommodated within their respective respositories so that the possibility of damage to the veneers is minimized.

According to the method of this invention. a backing sheet having an adhesive coated on one face thereof is supported horizontally at a prescribed height above the plant floor level, with the adhesive-coated face directed downwardly. A frame having a plurality of open-top repositories therein adapted to accommodate strips of veneers in neat stacks respectively are then elevated from below the horizontally supported hacking into substantial contact therewith. The stacks of veneers are succeedingly elevated relative to the frame until the uppermost veneers ofthe respective stacks come into contact with the adhesive-coated lower face of the backing sheet. With the uppermost veneers thus adhering to the backing sheet, the remaining stacks of veneers and the frame are successively lowered away therefrom.

In order to carry out the above summarized method, this invention further provides an apparatus comprising first lift means for imparting up-and-down motion to a platform supporting the aforesaid frame thereon. and second lift means mounted on the platform for imparting up-and-down motion to the movable bottoms of the repositories relative to the frame. The apparatus also includes overhead conveyor means for successively carrying the backing sheets to and away from a prescribed position above the framc, so that decorative sheets can be manufactured continuously on a full automatic basis.

The features which are believed to be novel and characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its method and apparatus, together with the further objects and advantages thereof, will be best understood from the following description taken in conjunction with the accompanying drawings which illustrate, by way of example only, a preferred embodiment of the invention and in which like reference numerals denote like parts throughout the views.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings:

FIG. 1 is a perspective view of the apparatus for the manufacture of decorative sheets constructed by way of a preferred embodiment of this invention, parts of the apparatus being shown broken away to show other parts in detail, and

FIG. 2 is a combined side elevational and vertical sectional view of the preferred embodiment of the invention, with the vertical section taken substantially along the vertical plane passing through line ll-Il in FIG. 1.

DETAILED DESCRIPTION As seen in both FIGS. 1 and 2, a platform 12 of rectangular shape is supported by first lift means generally designated by the numeral 11 so as to be movable up and clown relative to a stationary base plate 10. The first lift means 11 comprises a pair of power cylinders 13, which may be of the type actuated either hydraulically or pneumatically and mounted centrally at opposite edges of the base plate 10. The power cylinders 13 are coupled to the base plate 10 each at the cylinder head end thereof, and their piston rods 14 are coupled to respective ends of a rod 16 extending between and through the crossing points of X-shaped pairs of links 15 operatively interconnecting the base plate 10 and the platform 12 at opposite edges thereof. It will be seen from the drawings that each of the links 15 carries a roller 17 at one end thereof which is adapted to roll over either of rails 18 and 19 secured to the lower surface of the platform 12 and the upper surface of the base plate 10, respectively. The other end of each link 15 is rotatably pinned to and supported by the platform 12 or the base plate 10.

As best illustrated in FIG. 1, four posts 20 are mounted vertically upwardly on the platform I2, each at one corner thereof, and a rectangular frame 21 is resiliently supported by these posts 20 through springs 22. The inner space of the frame 21 is divided by parallel spaced partitions 23 into a plurality of repositories 24 each adapted to accommodate a stack of veneer sheets 26. Preferably, these partitions 23 are formed of thin sheets of stainless steel or the like, each with a 3 width equal to the height of the frame 21. and the mirti tions are so supported within the frame that the uppe edges of the former are csactl) flush with those of the latter.

Below the frame 21. a plurality of substantially hosshaped support st uctures 2. are fixedlt mounted on the platform 12 in parallel spaced relationship to each other in vertical registration with the respective repositories 24. Each of the support structures 25 is adapted to support second lift means 28 which imparts Lip-anddown motion to a movable bottom 27 of each repository 24, and hence to each stack of veneers 26. relative to the frame 21. An adjustment device 30 is provided between each support structure 25 and each movable bottom 27 in order to adjust the height of the latter so that the tops of all the stacks of veneers 26 will be on one and the same level. The adjustment device 30 comprises two opposed pairs of links 29 each pair of which are turnably and adjustably interconnected at their mid-portions and are further turn-ably coupled to each support structure 25 and movable bottom 27, respectively, each at one end thereof The aforesaid second lift means 28 comprises a pair of spaced apart screw rods 31 rotatably extending vertieally through each support structure 25 to upper ends thereof rigidly coupled to the corresponding one of the movable bottoms 27. As best shown in FIG. 1, an externally toothed ring gear 32 is mounted on one ofthe pair of screw rods 31 so as to be rotatable relative to the support structure but incapable of displacement in the axial direction of that one screw rodr the ring gear being internally screw threaded to mate with the external threads ofthe screw rod. The ring gear 32 is in mesh with a pinion 34 fixedly mounted on the output shaft of an electric motor 33 having a speed reduction device of any known or suitable construction.

A sprocket wheel 35 is also rotatably mounted on the one screw rod 31 and is rigidly coupled via a sleeve to the ring gear 32 for simultaneous rotation therewith. Another sprocket wheel 36 is screw-threadedly mounted on the other screw rod 31 so as to be rotatable relative to the same but incapable of displacement in the axial direction thereof. Thus, through an endless chain 37, the sprocket wheels 35 and 36 are caused to rotate synchronously to impart up anddown motion to the movable bottom 27 relative to the frame 21.

Although not shown in the drawings, it is assumed that suitable shock absorbing means are provided between the stacks of decorated veneers 26 and the movable bottoms 27 of the repositories 24 in order to cushion the impact with which the stacks of veneers contact a backing sheet 38 shown in F16. 2. it will be recalled that the frame 21 is resiliently supported by the springs 22 in order to cushion the impact of its contact with the backing sheet 38. Both the stacks of veneers 26 and the frame 21 are thus resiliently supported against forces exercised in the vertical direction.

As illustrated in HQ. 2, means for conveyance of the backing sheet 38 is provided above the frame 21 and so forthv This conveyor means comprises a horizontal overhead rail 39. and at least a pair of arms 41 supported by carriages 40, respectively, which move along the rail 39. The arms 41 include means for holding each backing sheet 38 either by suction or electromagnetism in accordance with the prior 11ft. Each backing sheet 38 is thus supported horizontally by the arms 41 and. when brought over the frame 21 by the conveyor means, is

4 held in exact registration therewith with the aid ofstops 42 provided on one edge of the frame. it should be noted that the backing sheet 38 is stopped at such a height above the frame 21 that when fully elevated by the first lift means 11. the frame will make substantial contact therewith.

The preferred embodiment of the invention being constructed substantially as hereinbefore described. the veneers to be adhered to each backing sheet 38 are stacked up on the movable bottoms 27 of the reposito ries 24. The adjustment 30 provided to the movable bottom 27 of each repository 24 may then be operated in order that the tops of the stacks of veneers 26 thus formed may all be on one and the same level. it will be seen from FIG. 2, however, that the tops of all the veneer stacks 26 must be held lower than the top of the frame 21 during the normal inoperative condition of the apparatus, that is, while the movable bottoms 27 of the repositories 24 are in their depressed position.

The backing sheet 38 in the form of plywood, fiber hoard, sheet metal or like sheet of relatively rigid material is conveyed to its predetermined position above the frame 21 while the same is held in its lowered position by the first lift means 11. it is assumed that the lower face of the backing thus conveyed to the predeter mined position is already coated with an adhesive which may most suitably be any one of such synthetic resin adhesives as the emulsions of vinyl acetate resins, the initial condensation products of urea resins, and melamine denatured urea resins.

The power cylinders 13 of the first lift means 11 are now actuated to elevate the frame 21 toward the hacking sheet 38 through the platform 12 and the posts 20. The upward motion of the first lift means 11 is automatically stopped by a limit switch, not shown, upon substantial contact ofthc frame 21 with the lower face of the backing sheet 38. Succeedingly, the motors 33 of the second lift means 28 are set in motion to rotate the ring gears 32 and the sprocket wheels 35 and 36 and hence to cause the upward motion of the movable bottoms 27 through the screw rods 31. The stacks of veneers 26 on the movable bottoms 27 are thus forced upwardly relative to the frame 21 and its partitions 23 until the uppermost veneers of the respective stacks come into contact with the adhesive-coated lower face of the backing sheet 38.

Upon adhesion of the uppermost veneers to the lower face of the backing sheet 38, the upward motion of the second lift means 28 is automatically suspended by a photoelectric element or elements of any known or suitable type, now shown, which may be mounted be tween the partitions 23 of the frame 21. The motors 33 of the second lift means 28 are further set in rotation again, this time of the reverse direction, to cause the descent of the stacks of remaining veneers to their preassigned lowermost positions within the repositories 24. The reversed rotation of the motors 33 is also automatically terminated by a limit switch or switches, not shown, mounted at the preassigned lowermost positions of the second lift means 28 or of the movable bottoms 27.

The powcr cylinders 13 of the first lift means 11 are succeedingly actuated again to cause the descent of the frame 2] and so forth away from the backing sheet 38 having the uppermost veneers of the respective stacks 26 adhered to its lower face as above stated. This backing is then transported to the succeeding hot pressing process by the conveyor means. while the next backing sheet similarly having a layer of adhesive on its lower face is brought to the predetermined position above the frame 21 now held in its lowermost position together with the stacks of veneers 26 accommodated in its repositories 24. Thereafter. the first and the second lift means 11 and 28 are succesa-zively set in motion again to repeat the above described cycle of operation.

What is claimed is:

l. A method of manufacturing decorative sheets each comprising a relatively rigid backing sheet and a plurality of veneers bonded to one face of the backing sheets, said method comprising consecutively repeated operational cycles each comprising the steps of:

supporting the backing sheet horizontally at a predetermined height above the floor level. said backing sheet being coated with a layer of adhesive on its lower face; elevating a frame from below said backing sheet into contact therewith, the interior of said frame being partitioned into a plurality of repositories adapted to accommodate stacks of the veneers respectively;

elevating said stacks of veneers relative to said frame until the uppermost veneers of the respective stacks Contact the lower face of said backing sheet over the layer of adhesive coating thereon.

lowering the remaining stacks of veneers relative to said frame away from said backing sheet having said uppermost veneers adhering to its lower face; and

lowering said frame away from said backing sheet together with said remaining stacks of veneers accommodated in said repositories thereof.

2. An apparatus for manufacturing decorative sheets each comprising a relatively rigid backing sheet and a plurality of veneers bonded to one face of the backing sheet, said apparatus comprising:

a base structure;

a platform disposed above said base structure;

first lift means adapted to impart up-and-down motion to said platform relative to said base structure;

a rectangular frame resiliently supported on said platform and having a plurality of partitions dividing the internal space of said frame into a plurality of open-top repositories adapted to accommodate stacks of veneers respectively, said repositories having vertically movable bottoms on which said stacks of veneers are deposited;

second lift means adapted to impart up-and-down motion to said movable bottoms of said repositories relative to said frame: and

conveyor means for carrying each backing sheet coated with an adhesive on its lower surface to and away from a predetermined position above said frame said first lift means lifting said frame to each backing sheet placed in said predetermined position;

said second lift means thereupon lifting all stacks thereby to press the uppermost veneers ofall stacks simultaneously against the adhesive coated lower surface of the backing sheet and thereby causing said veneers to adhere to said uppermost lower sur' face.

3. The apparatus as defined in claim 2. wherein said second lift means comprises:

at least a pair of spaced-apart screw rods rotatably extending vertically through a support structure mounted on said platform below each of said movable bottoms of said repositories, the upper ends of said pair of screw rods being secured to the corresponding one of said movable bottoms;

an externally toothed ring gear screw-threadedly mounted on one of said pair of screw rods, said ring gear being supported by said support structure so as to be rotatable relative to the same but incapable of displacement in the axial direction of said one screw rod;

a first sprocket wheel rotatably mounted on said one screw rod an coupled to said ring gear for simultaneous rotation therewith;

a second sprocket wheel screw-threadedly mounted on the other of said pair of screw rods, said second sprocket wheel being supported by said support structure so as to be rotatable relative to the same but fixed in displacement in the axial direction of said other screw rod;

an endless chain interconnecting said first and second sprocket wheels; and

drive means adapted to impart rotation to said ring gear relative to said support structure whereby said pair of screw rods move synchronously up and down relative to said support structure.

4. The apparatus as defined in claim 3, further in cluding adjustment means provided between said movable bottoms of said repositories and said support structures respectively, said adjustment means being adapted to adjust the height of each of said movable bottoms of said repositories so that the tops of said stacks of veneers are all settable on one and the same level.

5. The apparatus as defined in claim 2 further including stop means formed on one edge of said frame to stop each backing sheet carried by said conveyor means at said predetermined position above said frame. k 

1. A method of manufacturing decorative sheets each comprising a relatively rigid backing sheet and a plurality of veneers bonded to one face of the backing sheets, said method comprising consecutively repeated operational cycles each comprising the steps of: supporting the backing sheet horizontally at a predetermined height above the floor level, said backing sheet being coated with a layer of adhesive on its lower face; elevating a frame from below said backing sheet into contact therewith, the interior of said frame being partitioned into a plurality of repositories adapted to accommodate stacks of the veneers respectively; elevating said stacks of veneers relative to said frame until the uppermost veneers of the respective stacks contact the lower face of said backing sheet over the layer of adhesive coating thereon; lowering the remaining stacks of veneers relative to said frame away from said backing sheet having said uppermost veneers adhering to its lower face; and lowering said frame away from said backing sheet together with said remaining stacks of veneers accommodated in said repositories thereof.
 2. An apparatus for manufacturing decorative sheets each comprising a relatively rigid backing sheet and a plurality of veneers bonded to one face of the backing sheet, said apparatus comprising: a base structure; a platform disposed above said base structure; first lift means adapted to impart up-and-down motion to said platform relative to said base structure; a rectangular frame resiliently supported on said platform and having a plurality of partitions dividing the internal space of said frame into a plurality of open-top repositories adapted to accommodate stacks of veneers respectively, said repositories having vertically movable bottoms on which said stacks of veneers are deposited; second lift means adapted to impart up-and-down motion to said movable bottoms of said repositories relative to said frame; and conveyor means for carrying each backing sheet coated with an adhesive on its lower surface to and away from a predetermined position above said frame, said first lift means lifting said frame to each backing sheet placed in said predetermined position; said second lift means thereupon lifting all stacks thereby to press the uppermost veneers of all stacks simultaneously against the adhesive coated lower surface of the backing sheet and thereby causing said veneers to adhere to said uppermost lower surface.
 3. The apparatus as defined in claim 2, wherein said second lift means comprises: at least a pair of spaced-apart screw rods rotatably extending vertically through a support structure mounted on said platform below each of said movable bottoms of said repositories, the upper ends of said pair of screw rods being secured to the corresponding one of said movable bottoms; an externally toothed ring gear screw-threadedly mounted on one of said pair of screw rods, said ring gear being supported by said support structure so as to be rotatable relative to the same but incapable of displacement in the axial direction of said one screw rod; a first sprocket wheel rotatably mounted on said one screw rod an coupled to said ring gear for simultaneous rotation therewith; a second sprocket wheel screw-threadedly mounted on the other of said pair of screw rods, said second sprocket wheel being supported by said support structure so as to be rotatable relative to the same but fixed in displacement in the axial direction of said other screw rod; an endless chain interconnecting said first and second sprocket wheels; and drive means adapted to impart rotation to said ring gear relative to said support structure whereby said pair of screw rods move synchronously up and down relative to said support structure.
 4. The apparAtus as defined in claim 3, further including adjustment means provided between said movable bottoms of said repositories and said support structures respectively, said adjustment means being adapted to adjust the height of each of said movable bottoms of said repositories so that the tops of said stacks of veneers are all settable on one and the same level.
 5. The apparatus as defined in claim 2, further including stop means formed on one edge of said frame to stop each backing sheet carried by said conveyor means at said predetermined position above said frame. 